Celect - size and quantity, when choosing on the phone, it does not immediately change the price, what should I do?

Question

css

Hello.
A small problem was drawn, there is a website, the website has sizes and quantity, the choice in the select, on the computer, etc., everything works fine, we choose a different size and the price changes, each size has its own price, we select the quantity of goods, everything is ok, it’s a plus, but if you go from the phone, then you choose there and doesn’t change anything, let’s say the size, you chose it and he didn’t change the price, he pressed the size list again to open the list and he immediately changed the price, because somehow it works, why is that on the phone? asked a friend to check with him immediately changes, he has an android, I have an android and did not immediately change the price.
What could be the problem and how can it be solved?
HTML
Select of this kind.

<select name="kolvo" id="kolvo" class="cvet_product">
<option value=1>1</option>
<option value=2>2</option>
<option value=3>3</option>
<option value=4>4</option>
<option value=5>5</option>
<option value=6>6</option>
<option value=7>7</option>
<option value=8>8</option>
<option value=9>9</option>
<option value=10>10</option>
<option value=11>11</option>
<option value=12>12</option>
<option value=13>13</option>
<option value=14>14</option>
<option value=15>15</option>
<option value=16>16</option>
                <option value=17>17</option>
                <option value=18>18</option>
                <option value=19>19</option>
                <option value=20>20</option>
                <option value=21>21</option>
                <option value=22>22</option>
                <option value=23>23</option>
                <option value=24>24</option>
                <option value=25>25</option>
                <option value=26>26</option>
                <option value=27>27</option>
                <option value=28>28</option>
                <option value=29>29</option>
                <option value=30>30</option>
                <option value=31>31</option>
                <option value=32>32</option>
                <option value=33>33</option>
                <option value=34>34</option>
                <option value=35>35</option>
                <option value=36>36</option>
                <option value=37>37</option>
                <option value=38>38</option>
                <option value=39>39</option>
                <option value=40>40</option>
                <option value=41>41</option>
                <option value=42>42</option>
                <option value=43>43</option>
                <option value=44>44</option>
                <option value=45>45</option>
                <option value=46>46</option>
                <option value=47>47</option>
                <option value=48>48</option>
                <option value=49>49</option>
                <option value=50>50</option>
                <option value=51>51</option>
                <option value=52>52</option>
                <option value=53>53</option>
                <option value=54>54</option>
                <option value=55>55</option>
                <option value=56>56</option>
                <option value=57>57</option>
                <option value=58>58</option>
                <option value=59>59</option>
                <option value=60>60</option>
                <option value=61>61</option>
                <option value=62>62</option>
                <option value=63>63</option>
                <option value=64>64</option>
                <option value=65>65</option>
                <option value=66>66</option>
                <option value=67>67</option>
                <option value=68>68</option>
                <option value=69>69</option>
                <option value=70>70</option>
                <option value=71>71</option>
                <option value=72>72</option>
                <option value=73>73</option>
                <option value=74>74</option>
                <option value=75>75</option>
                <option value=76>76</option>
                <option value=77>77</option>
                <option value=78>78</option>
                <option value=79>79</option>
                <option value=80>80</option>
                <option value=81>81</option>
                <option value=82>82</option>
                <option value=83>83</option>
                <option value=84>84</option>
                <option value=85>85</option>
                <option value=86>86</option>
                <option value=87>87</option>
                <option value=88>88</option>
                <option value=89>89</option>
                <option value=90>90</option>
                <option value=91>91</option>
                <option value=92>92</option>
                <option value=93>93</option>
                <option value=94>94</option>
                <option value=95>95</option>
                <option value=96>96</option>
                <option value=97>97</option>
                <option value=98>98</option>
                <option value=99>99</option>
<option value=100>100</option>
</select>

js

jQuery(".vkorziny").on("click", function(){
  price = parseFloat(jQuery('#hiden-price').val());
  qty = parseFloat(jQuery("#kolvo").val());
  product_id = jQuery('#product_id').val();
  size_id = jQuery('#product_id').val();


function get_price() {	
  var count = parseFloat(jQuery("#kolvo").val());
  var id = jQuery("#size").val();
  var size_price = 0;	
  $.ajax({
    url: '/ajax/get_price',
    type: 'POST',
    async: true,
    data: {id: id},
    success: function (answer) {			
      size_price = parseFloat(answer);
      var price = count * size_price;
      jQuery('#cenarazmer span').html(number_format(price, 0, '.', '.'));
      jQuery('#hiden-price').val(size_price);
    }
  });	
}

jQuery("#kolvo").on("change", function () {
price = parseFloat(jQuery('#hiden-price').val());
qty = parseFloat(jQuery(this).val());
if (qty > 0) {
if (price) {
new_price = qty * price;
jQuery('#fullcena span').html(number_format(new_price, 0, '.', '.'));
}
}
return false;
});

Answer 1

Bro, there was exactly the same problem, you just need to use not onclick, but onchange to catch events for select, then it will work on the phone. And onchange will also work on the computer